The present invention relates to easily openable closure tapes for bags, and more particularly to perforated strips useful as closure tapes for bags.
Bulk consumer items (e.g., potting soil, seed, and animal feed as well as food products for service applications) are often packaged in large bags (e.g., pouches or satchels) for sale to the public. The weight of these bulk items often necessitates that the material for the bag be durable and tear-resistant. Typically, bulk item bags are made of a tear-resistant plastic, a tear-resistant paper-based material, or some combination of the two. However, opening such bulk item bags without the use of cutting instruments is often difficult due to the tear resistance of the bag material.
A solution to the foregoing problem was posed in U.S. Patent Application Publication No. 2003/0215165 entitled “Easy-Open Strip and Bags Incorporating the Same”. That application discloses an easy-open closure tape for a bag, which includes a base web, a frangible layer, and a tear bead. The base web has a pair of longitudinal edges with a pair of perforated tear lines running generally parallel to the longitudinal edges and substantially equidistant from the longitudinal edges. The frangible layer is attached to one side of the base web and is positioned over the perforated tear lines to obstruct the perforations on one side. The tear bead is attached to the frangible layer on the side opposite from the base web and is positioned generally centrally between the respective locations of the perforated tear lines. Preferably, the base web is formed from a material such as a thermoplastic polymer, a paper-based material, other multi-layer webs used in the packaging industry or a combination thereof. The frangible layer serves to seal the perforations, thereby keeping out small particles and insects and preventing small particles within the packages from leaking out. The frangible layer also aids in keeping moisture in or out.
There is a need for efficient and inexpensive methods of manufacturing packages having easily opened closure strips. There is also a need for alternative designs for easily opened closure strips.